Apparatus and method for transporting automobiles in an enclosed semi-trailer

ABSTRACT

The present invention relates to an apparatus and method for converting a semi-trailer or intermodal shipping container from carrying general freight cargo to carrying automobiles. More specifically, the present invention provides for a lift mechanism which is powered by the drive wheels of the automobile being carried by the lift so that a plurality of automobiles may be carried in two levels in an enclosed semi-trailer or intermodal shipping container. The method of the present invention is also adaptable to being employed in piggy back transportation of semi-trailers or intermodal shipping containers on railroad cars. The apparatus of the present invention is designed for flexibility in use and ease of assembly and disassembly which comprises lift assemblies based on the use of ball screws powered from flexible cable drives.

This is a division of application Ser. No. 08/013,042 filed on Feb. 4,1993 now U.S. Pat. No. 5,297,908.

BACKGROUND OF THE INVENTION TECHNICAL FIELD

The present invention relates to an apparatus and method fortransporting automobiles by converting a semi-trailer from carryinggeneral freight cargo to carrying automobiles. More specifically, thepresent invention provides for a lift mechanism which is powered by thedrive wheels of the automobile being carried by the lift so that aplurality of automobiles may be carried in two levels in an enclosedsemi-trailer. Alternative embodiments of the method of the presentinvention provide for transportation of automobiles by semi-trailersalone, by piggy-back transportation on railcars or by intermodalshipping containers. As used herein, the terms "semi-trailer" or"enclosed semi-trailer" should be understood to include standardintermodal shipping containers also.

DESCRIPTION OF THE PRIOR ART

The transportation of automobiles from the manufacturer to the dealer isnormally by means of specialized automobile hauling trailers, trucks andrailcars. Trailers and trucks designed for carrying automobiles areuniquely adapted for high efficiency in carriage of that particular typeof commodity and are not suitable for use as general freight carriers.General freight, by contrast, is normally carried in enclosedsemi-trailers which can carry a wide variety of goods since they do notpossess the unique specialized adaptations required for carryingautomobiles.

The two types of vehicles described above, namely the automobilecarrying trailer and the general freight carrying trailer, are thusadapted to their own particular mode of operation and are unable tocarry the type of freight for which the other is adapted. However, whilethe less specialized general freight carrying semi-trailer is able tohaul a wide variety of goods, excepting automobiles, the automobilecarrying trailer is so highly specialized that it is unable to haul anyother type of freight other than the automobiles for which it isuniquely adapted. Thus, while general freight carrying trailers arenormally able to arrange for transportation of goods on both legs of around trip, the automobile carrying trailer is normally left to returnempty from a particular designation.

The consequence of this situation is that automobile carrying trailersand trucks are often under-utilized which translates into high per-milecost and generally higher freight rates.

Another disadvantage to the use of the specialized types of automobilecarrying trailers is that they are generally open to the elements whichexposes their cargo to vandalism and damage from environmental factors.

To solve the problems identified above, the present invention providesfor an apparatus and method for converting an enclosed semi-trailer fromthe carriage of general freight to the carriage of automobiles. Thisconcept of converting semi-trailers for carrying both general freightand automobiles is not new. For example, U.S. Pat. No. 5,051,046 issuedto Oren on Sep. 24, 1991 for "Semi-Trailer Convertible for HaulingAutomobiles" discloses an enclosed semi-trailer having tracks for thesupport of an upper level of automobiles. Likewise, U.S. Pat. No.4,786,222 issued to Blodgett on Nov. 22, 1988 for "Folding AutomobileStorage Deck Assembly" discloses a semi-trailer equipped to be used foreither automobile or general freight transportation in which swivelingdeck sections are provided for carrying two layers of automobiles. Alsothe same concept has been applied to the transportation of automobilesin standard intermodal shipping containers; e.g., U.S. Pat. No.4,911,590 issued to Green on Mar. 27, 1990 for "Automobile Loading Rackand Method for Loading into Containers." Other patents which disclosethe general concept of converting an enclosed trailer to the carriage ofautomobiles include U.S. Pat. Nos. 2,668,734 and 2,636,772. Also ofinterest are U.S. Pat. Nos. 4,701,086, 2,659,318 and 2,432,228.

Each of these patents generally disclose some means for carryingautomobiles in a two-level configuration through the use of ramps orelevators.

In each of the patents cited above, the elevator or ramp mechanism ispowered by an external source, for example, hydraulic rams or electricmotors. The present invention provides for a lift mechanism which isoperated by the drive wheels of the automobile being lifted into theupper position. Various concepts for employing the drive wheels of avehicle to power a lift or elevator have been disclosed in the priorart. Examples of such concepts are disclosed in U.S. Pat. Nos.3,637,099, 3,521,728, 2,754,933, 2,579,688, 2,538,517, 2,497,472 and1,751,874. Such concepts have even been disclosed for use in connectionwith toy vehicles; e.g., U.S. Pat. No. 4,582,500. To the best knowledgeof the inventor, however, the concept of an automobile powered lift hasnever been applied to the unique problems in converting an enclosedsemi-trailer from the carriage of general freight to the carriage ofautomobiles.

It is important to note that many of the same problems identified abovein relation to specialized trailers and trucks for the carriage ofautomobiles also are true of the specialized railcars required for thetransportation of automobiles by rail. The apparatus and method of thepresent invention is also adaptable to being employed in the railtransportation of automobiles through the use of the "piggyback" systemfor the transportation of enclosed semi-trailers. By preloadingautomobiles into semi-trailers using the method and apparatus of thepresent invention, greater flexibility and efficiency in the railtransportation of automobiles is possible. In addition, the method andapparatus of the present invention may also be applied to loading andtransportion of automobiles in standard intermodal shipping containers.Loading automobiles into shipping containers has all the advantages ofshipping semi-trailers "piggyback" by rail and in addition shippingcontainers may be double stacked for even greater efficiencies.Throughout the following discussion of the present invention, thepreferred embodiments, and claims, the use of the terms "semi-trailer"or "enclosed semi-trailer" are intended to embrace intermodal shippingcontainers also except where specifically distinguished.

SUMMARY OF THE INVENTION

The present invention is for a method and apparatus for transportingautomobiles by converting enclosed semi-trailers to automobile carriersutilizing a lift powered by the drive wheels of the automobile itself.By using this mechanism to operate the lift, the entire apparatus can begreatly simplified and many of the complications inherent in prior artdesigns can be eliminated. Simplifying the design and keeping theworking apparatus to a minimum is highly significant in developing aworkable solution to the problem of converting an enclosed semi-trailerfrom the carriage of general freight to the carriage of automobiles.Heavy and cumbersome equipment, particularly, the more complicatedpieces of apparatus disclosed in the prior art, render the conceptunworkable by adding excessive weight, by interfering with the use ofthe semi-trailer for the transportation of general freight and byreducing the reliability of the apparatus.

Another significant aspect of the present invention is inherent in itslight weight, ease of assembly or disassembly and minimal interferencewith the use of the semi-trailer for general freight.

In the present invention, a plurality, particularly two or three,automobile-powered lifts are positioned in an enclosed semi-trailer. Anautomobile may be driven onto a lift where one carriage holds thenon-driven wheels and another carriage holds the driven wheels. Thedriven wheels can be put into motion, which causes a roller under eachof the driven wheels to rotate. The rotational motion of the rollers aretransmitted by flexible shafts to gear boxes associated with foursupporting columns, one adjacent to each wheel of the automobile. Eachsupport column contains a ball screw which is mechanically connected tothe carriages supporting the driven and non-driven wheels. Action of theball screws, therefore, lifts or lowers the automobile depending on thedirection of motion of the driven wheels. Once an automobile has beenlifted into position, another automobile may be driven underneath thelift. In this way automobiles are loaded in stacks two vehicles highuntil the entire semi-trailer is filled. In order to unload thesemi-trailer, the process is simply reversed.

An alternative embodiment of the present invention carries the methodone step further by transporting the filled semi-trailers piggy-backedon railcars. This has the advantage of avoiding the difficult andcumbersome loading and unloading of automobiles directly onto and off ofspecialized automobile carrying railcars. Further, this mode oftransportation offers the possibility of greatly increasing theefficiency of transportation of automobiles and the utilization ofsemi-trailers. As noted above there is usually a problem withspecialized automobile carrying trailers being underutilized. Thepresent invention offers a solution to this problem. Once a semi-trailerutilizing the apparatus of the present invention is unloaded at itsdestination, the automobile-powered lifts may be easily disassembled andremoved from the semi-trailer. The trailer is then free to be returnedto general freight service. The disassembled lifts may be accumulatedand at periodic intervals shipped to the point of origin to begin theprocess over again. This method is only possible due to the employmentof the automobile-powered aspect of the present invention which obviatesthe need for complicated external power sources.

It is thus an object of the present invention to increase productivityand efficiency in the utilization of semi-trailers for transportingautomobiles by allowing semi-trailers to be used for both thetransportation of automobiles and for the transportation of generalfreight.

A further object of the present invention is to provide a secureenclosed environment for the transportation of automobiles in which thetransported automobiles are less exposed to the hazards of vandalism andthe environment, including thrown rocks, mud, water and the like.

It is also an object of the present invention to provide an economicalmeans for converting an enclosed semi-trailer to the carriage ofautomobiles, and to provide for a mechanism which is simple, efficient,cost effective and which requires low maintenance.

Other advantages and objects of the present invention will becomeapparent from the following detailed description of the preferredembodiments, with particular reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partially cut away elevation view of a typical semi-trailershowing three sets of automobile powered lifts in place with sixautomobiles positioned in three stacks of two each.

FIG. 2 is a partial exploded perspective view of one front supportcolumn and one rear support column showing the relationship of the frontcarriage and the rear carriage to the front and rear support columns.

FIG. 3 is a partial perspective view of the top of a support columnshowing a lock nut arrangement to prevent rotation of the screw.

FIG. 4 is a partial perspective view detailing the attachment of thecarriage to the support column.

FIGS. 4a and 4b are detailed sectional views showing the means ofattachment of the carriage to the support column.

FIG. 5 is an exploded perspective view partially cut away to show thescrew assembly within the support column and the means of mechanicalconnection of the screw assembly to the carriage and the gearbox.

FIG. 6 is an exploded perspective view of the carriage and supportcolumns showing the removable roller assembly.

FIG. 7 is a partial sectional view of the screw assembly within thesupport column detailing the ball nut and means of attachment to thecarriage.

FIG. 8 is a sectional detailed view of the base of a support column andgear box.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The overall appearance of the present invention may be described withreference to FIGS. 1, 2 and 6. The apparatus of the present invention isan automobile-powered automobile lift to be used in conjunction with anenclosed semi-trailer 10. As shown in FIG. 1, three of theautomobile-powered automobile lifts 11 of the present invention areshown in position in the enclosed semi-trailer 10. Depending on thelength of the semi-trailer 10 and the lengths of the automobiles 12, upto three stacks of two automobiles 12 each can be loaded into thesemi-trailer 10.

Each lift 11 comprises a front lift assembly 13 and a rear lift assembly14 as shown on FIGS. 1 and 2. Most of the components of the front liftassembly 13 and the rear lift assembly 14 are identical.

With reference to FIGS. 2 and 6, the front lift assembly 13 includes apair of front support columns 15, 16 which are spaced apart and bracedby a pair of transverse braces 17. The transverse braces 17 are rigidlyattached to left and right U channels 18, 19 which in turn contain leftand right front column gear boxes 20, 21 which support left and rightfront support columns 15 and 16 respectively. The front lift assembly 15also comprises a front wheels carriage 22. The front wheels carriage 22supports a removable roller assembly 23. The front lift assembly 13 isalso provided with ramps 24 to allow an automobile 12 to be driven overthe transverse braces 17. The ramps 24 also act to restrain the wheelsof an automobile 12 loaded into the lower position when the lift 11 isin the upper position.

The rear lift assembly 14 is identical to the front lift assembly 13 asdescribed above with the exception of the removable roller assembly 23.In place of the removable roller assembly 23, the rear lift assembly 14is provided with a pair of removable wheel receptacles 25, one of thepair of which is shown in FIG. 2. The wheel receptacles 25 serve asdevices to receive and restrain each of the non-driven wheels of theautomobile 12. The non-driven wheels may be either the front or the rearwheels of the automobile 12 depending upon whether the automobile 12 isa rear drive or front drive model.

In addition to the features described above, both the front liftassembly 13 and the rear lift assembly 14 are strengthened againstmovement backwards or forwards by means of braces 26. A typical bracingscheme is shown in FIG. 2 in which the braces 26 are attached to theleft front support column 15 and to the left front U channel 18 in anangled relationship so as to brace the support column 15 againstmovement backwards and forwards. An identical bracing arrangement isprovided for the right front support column 16 and the rear supportcolumns 27.

It is important to note that the front lift assembly 13 and the rearlift assembly 14 are independent structures attached only by powertakeoff shafts 28 as will be described more fully below. The spacingbetween the front lift assembly 13 and the rear lift assembly 14 can,therefore, be adjusted so as to accommodate automobiles 12 of varyingwheel base. In practice the front lift assembly 13 and the rear liftassembly 14 may be fastened to the semi-trailer 10 in various ways,including nails, screws or bolts. It is thus possible to provide foreither permanent or semipermanent installation of the present inventionin a semi-trailer 10.

Both the front support columns 15, 16 and the rear support columns 27contain ball screw assemblies 29. The functioning of the ball screwassembly 29 may be described with reference to FIG. 5. While FIG. 5shows only front support column 15, the construction for front supportcolumn 16 and rear support columns 27 are identical. As describedpreviously, front support column 15 rests upon gear box 20, which inturn is rigidly fastened to the inside of U-channel 18. The ball screwassembly 29 comprises the screw 30, the ball nut 31, the carriageattachment block 32, an upper bearing plate 33, and a lower bearingblock 34. The lower bearing block 34 is mounted to the gear box 20. Thescrew 30 rides in and bears upon the lower bearing block 34. The upperbearing plate 33 located at the top of the support column 15 supportsand guides the top of the screw 30. The arrangement of the carriageattachment block 32 relative to the ball nut 31 is shown in more detailin FIG. 7. The screw 30 passes through the ball nut 32 to which it isoperatively connected by a series of ball bearings 57 which ride incomplementary grooves in the screw 30 and the ball nut 31. The ballbearing return 35 is shown on FIG. 5. It may thus be seen that rotationof the screw 30 causes the ball nut 31 to be moved up and down along thesupport column 15. The carriage attachment block 31 is rigidly affixedto the ball nut 31 and is thus carried along with the ball nut 31 as thescrew 30 rotates. The carriage attachment block 32 is provided with aprojection 36. The projection 36 extends through a slot 37 in supportcolumn 15 as shown on FIG. 5. Again, with reference to FIG. 5 arectangular sleeve 38 rides along the outside of support column 15.Rectangular sleeve 38 contains an opening 39 through which projection 36extends. It may be seen, therefore, that the ball nut 31, the carriageattachment block 32 and the sleeve 38 mechanically function as a singleunit which moves up and down the support column 15 as the screw 30 isrotated. The projection 36 extends far enough beyond the rectangularsleeve 38 to extend into an opening 40 on the carriage support plate 41which is rigidly attached to rectangular sleeve 38. The carriage supportplate 41 is provided with a pair of angle brackets 42 which provide forthe means for detachably mounting the front wheels carriage 22 betweenthe left support column 15 and the complementary structure on the rightsupport column 16. Furthermore, the end plate 43 is provided with anglebrackets 59 which fit over carriage support plate 41.

The mounting of the front support carriage 22 to the carriage supportplate 41 is described with reference to FIG. 4. The end plate 43 of thefront support carriage 22 fits over and into the space formed betweenthe brackets 42 and the support plate 41. Also as shown is FIG. 4a thespace formed between brackets 59 and end plate 43 fits over carriagesupport plate 41. As shown in detail in the sectional drawing of FIG.4b, the weight of the front support carriage is, therefore, born by thesleeve 38 through the support plate 41 and brackets 42. It may,therefore, easily be seen that rotation of the screw 30 thus results inraising or lowering of the support carriage 22. While the operation ofthe screw 30 resulting in movement of the support carriage 22 has beendescribed with relation to the left front support column 15, it is to beunderstood that identical and complementary features on right supportcolumn 16 operate to form the completely functioning front lift assembly13. Likewise, the rear support carriage 44 operates in conjunction withrear support columns 27 in precisely the same fashion to form the rearlift assembly 14.

It is important to note that due to the ease of disassembly of the frontsupport carriage 22 from the front support columns 15, 16 anddisassembly of the rear support carriage 44 from the rear supportcolumns 27, and furthermore due to the lack of structural attachmentsbetween the front lift assembly 13 and the rear lift assembly 14, theentire structure can be easily assembled and disassembled for storage.

The operation of the front support column gear boxes 20, 21 and the rearsupport column gear boxes 45 are explained with reference to FIG. 8.FIG. 8 provides a sectional view of front support column gear box 20,however, it should be understood that except with respect to thediscussion of gear ratios which follows, the construction and operationof gear boxes 21, 45 are identical. It may be seen from FIG. 8 thatscrew 30 bears on bearing block 34 which in turn bears on gear box 20.Left front support column 15 is attached to bearing block 34. Screw 30extends by a screw shaft 46 through bearing block 34 into the interiorof gear box 20. Screw shaft 46 is attached to a bevel gear 47. Bevelgear 47 meshes with complementary bevel gear 48 which converts thevertical rotation of screw 30 into the horizontal rotation of driveshaft49 to which complementary bevel gear 48 is attached. While in practicethe gear ratio between bevel gears 47 and 48 may be constant among thegears of all four support columns 15, 16, 27, it has been found to bedesirable to vary the gear ratios between the front columns 15, 16 andthe rear columns 27. If all the driveshafts 49 are driven at the samerate, varying the gear ratios causes the screws 30 to rotate at adifferent rate in the front lift assembly 13 versus the rear liftassembly 14. A 2:1 drive ratio for the front lift assembly 13 versus a3:1 drive ratio for the rear lift assembly 14 results in the frontsupport carriage 22 being advanced faster and, therefore, higher thanthe rear support carriage 44. The significance of this arrangement willbe discussed below in conjunction with the operation of the overallinvention.

The construction and operation of the removable roller assembly 23 isdescribed with reference to FIG. 6. As described above, the removableroller assembly 23 is placed in and supported by the front supportcarriage 22. The roller assembly 23 may be removed from the supportcarriage 22 for disassembly of the entire invention or for otherpurposes as described below. The roller assembly 23 comprises a pair ofdrive wheel receptacles 50. Each drive wheel receptacle 50 includes adrive roller 51 and a pair of idler rollers 52. The idler rollers 52 arerotatably supported by the drive wheels receptacles 50. The idlerrollers 52 rotate freely and are not driven. The idler rollers 52 servesimply to provide a well to receive and support the drive wheels of anautomobile 12. The drive wheels of the automobile 12 rest upon the driverollers 51 with a sufficiently firm contact so that operation of thedrive wheels of the automobile 12 cause the drive wheels of theautomobile 12 to spin freely upon the supports provided by idler rollers52 and drive the drive rollers 51 into rotation. If necessary a springcould be used to bias the drive rollers 51 into firm contact with thedrive wheels of the automobile 12. The drive rollers 51 are connectedtogether by a drive roller shaft 58 which assures uniform rotation ofboth drive rollers 51. Each drive roller 51 is connected to a flexibleshaft 53. Each flexible shaft 53 connects to the driveshaft 49 of itsrespective gear box 20, 21. Each driveshaft 49 of the front liftassembly 13 is connected by a power takeoff shaft 28 to thecomplementary driveshafts 49 of the rear lift assembly 14.

Operation of the invention may be described as follows. Initially thefront support carriage 22 and the rear support carriage 44 are in alowered position. An automobile 12 is driven onto the support carriages22, 44 so that the drive wheels of the automobile 12 fall into the wellsprovided by the respective drive wheel receptacles 50. The non-drivenwheels rest in the wheel receptacles 25 of the rear lift assembly 14.The drive wheels of the automobile 12 are now in contact with the driverollers 51. Continued rotation of the drive wheels of the automobile 12cause the drive rollers 51 to rotate which in turn produces rotarymotion in the flexible shafts 53. The rotation of the flexible shafts 53drive the driveshafts 49 of the gear boxes 20, 21 of the front liftassembly 13. The driveshafts 49 of the front lift assembly also drivethe power takeoff shafts 28 which in turn drive the driveshafts 49 ofthe rear lift assembly 14. The gear boxes 20, 21, 45 then translate thehorizontal rotation of the driveshafts 49 into the vertical rotation ofthe screws 30. The rotation of the screws 30 therefore acts to lift boththe front support carriage 22 and the rear support carriage 44, thusraising the automobile 12. By appropriate adjustment of the gear ratiosas described above, the automobile 12 may be raised so that the front ofthe automobile 12 is raised to a higher elevation than the rear of theautomobile 12. The degree to which the automobile 12 is angled form thehorizontal is limited so that there is no danger of the wheels of theautomobile 12 being pulled from secure positions on either the frontlift carriage 22 or the rear support carriage 44. In practice thesuggested gear ratios described above have been found to be acceptable.The significance of this arrangement may be seen with respect to FIG. 1.By raising the front of the automobile 12 to a different elevation thanthe rear, the automobile 12 may be restrained from rearward motion whenthe semi-trailer 10 is put into forward motion. In addition, a secondautomobile may be driven under the first automobile. The ramps 24facilitate this process by allowing the second automobile to pass easilyover the transverse braces 17. The wells formed by the ramps 24 alsoserve to provide some restraint to motion by the second automobile. Byadjusting the orientation of the first automobile 12, the secondautomobile may be positioned under the first automobile more easily. Inaddition, a greater packing density in the semi-trailer 10 may beachieved. As can be seen from FIG. 1, once a first automobile is placedon the lift 11 and lifted to a raised position and a second automobileis moved into position under the first automobile, it is then possibleto continue to fill the semi-trailer 10 with a series of lifts 11 sothat stacks of two automobiles each may be created. A series of suchstacks, therefore, can be used to completely fill the semi-trailer 10.

Unloading of the semi-trailer 10 is thus accomplished in precisely thereverse fashion. The second automobile of the last stack is driven outof the semi-trailer 10. The first automobile in the raised position isstarted and its drive wheels used in the opposite direction to operatethe lift 11 so that it is lowered to the lowest position. After beingplaced in the lowest position, the first automobile is then driven outof the semi-trailer 10. In similar fashion each stack is unloaded untilthe semi-trailer 10 is completely unloaded. At this point, each of theautomobile powered lifts 11 may be disassembled and removed, allowingthe semi-trailer 10 to be converted to general freight usage or theautomobile powered lifts 11 may remain in position for further use intransporting automobiles.

While an automobile 12 is in the raised position on the presentinvention, it may be desirable to assure that the front support carriage22 and the rear support carriage 44 remain in the raised position. Alocking mechanism is provided as shown in FIG. 3. Again, this mechanismis described with reference to left front support column 15, but thesame mechanism may be used on each of the other support columns 16, 27.A hex nut 54 is rigidly fixed to the top of each screw 30 exterior ofthe upper bearing plate 33. A lock nut 55 is provided which is square inoutline to fit within the upper part of support column 15. The lock nut55 contains a hexagonal opening 56 which is sized to contain the hex nut54. When the lock nut 55 is in place over the hex nut 54, rotation ofthe screw 30 is prevented. This provides an additional safety measure toensure that once an automobile 12 is placed in the raised position itwill not be accidentally lowered. In addition to the precautionsmentioned above with respect to the use of the lock nut 55 and thevarying gear ratios which allow the automobile 12 to be placed in anupended position, there are also various restraint devices which arewell known in the prior art for securing an automobile for transit.These methods include, for example, straps to secure the axles of theautomobile 12 to the lift 11.

While the operation of the present invention has been described inreference to one particular mode of operation, it is also important tonote that the present invention may be operated with a great deal offlexibility due to the fact that the roller assembly 23 may be removedand repositioned in various configurations. For example, the rollerassembly 23 may be removed from the front lift assembly 13 andrepositioned to the rear lift assembly 14 to accommodate automobileswhich may be either front wheel or rear wheel drive. In addition asshown in FIG. 1, multiple lifts 11 may be installed in a singlesemi-trailer 10. A roller assembly 23 from one of the lifts 11 may bemoved to a position on another lift 11 so that an automobile 12 may beused to operate a separate lift 11. In addition, the same result may beobtained by attaching the flexible shaft 53 from the roller assembly 23of one lift 11 to the driveshafts 49 of a separate lift 11. Thisdiscussion does not exhaust all of the possible configurations that maybe employed with the present invention, all of which are contemplated tobe encompassed within the scope of this invention, and failure todiscuss a particular configuration does not imply exclusion of such aconfiguration from the scope of the present invention.

Once a semi-trailer 10 has been completely loaded in the fashion setforth above, the semi-trailer may then be transported to its destinationfor unloading. As an alternative embodiment to the method of the presentinvention, however, the semi-trailer 10 may be transported by railcar inthe fashion known as piggy-back transportation. In this system thesemi-trailer 10 may be loaded on a railcar for transportation to adestination at or near its final destination. Transportation by railoffers a number of advantages. For example, intermodal shippingcontainers adapted to piggy-back transportation may be actually loadedonto railcars in a two-container high or "double stack" configuration.This obviously offers great economies in transportation of automobiles.In addition, use of enclosed semi-trailers 10 for transportation ofautomobiles avoids environmental hazards that may be common to the opencarriers commonly employed by railroads. In addition since theautomobiles 12 are already arranged and stored in the semi-trailer 10,there is no need for railroad personnel to be involved in the cumbersomeand inefficient process of loading automobiles individually onto arailcar.

An alternative embodiment of the method of the present invention for thetransportation of automobiles 12 in an enclosed semi-trailer 10 usingautomobile powered automobile lifts 11 relates to the use of piggy-backrailroad transportation as described above. One or more semi-trailers 10may be loaded with automobiles 12 as described above. The semi-trailersmay then be loaded onto railcars for transportation to a point at ornear their ultimate destination. Upon arrival at the ultimatedestination and upon unloading of the automobiles 12, the automobilepowered lifts 11 may be disassembled and removed from the semi-trailer10. The semi-trailer 10 may then be employed for general freightpurposes. Since it would be quite unusual for there to exist a need totransport automobiles from the point of destination to the point oforigin, the disassembled lifts 11 may be accumulated and returned to thepoint of origin after a number of lifts 11 have been accumulated. Thisallows a limited number of semi-trailers 10 to be used for the return ofthe disassembled lifts 11 to the point of origin and avoids the commonproblem of specialized car-carrying trucks being returned empty to thepoint of origin.

While the apparatus and method of the present invention have beendescribed with reference to certain preferred embodiments andalternative preferred embodiments, it is to be understood that variousmodifications to the preferred embodiments would be obvious to oneskilled in the art and that the above description is intended to beexemplary and not by way of limitation to the full scope of theinvention which is set forth in the following claims.

What is claimed is:
 1. A method for transporting automobiles in anenclosed semi-trailer having a forward end, a rearward end and a floor,comprising the steps of:(a) installing an automobile-powered automobilelift into said semi-trailer, said lift having means to receive a firstautomobile having drive wheels at a first position lowered to theapproximate level of said floor and means operated by said drive wheelsof said first automobile for raising said lift to a second position at asufficient elevation above said floor to allow a second automobile to bepositioned beneath said first automobile; (b) placing said lift at saidfirst position; (c) driving said first automobile onto said lift; (d)operating said drive wheels of said first automobile to raise said liftto said second position; (e) driving said second automobile under saidlift containing said first automobile; and (f) repeating steps (a)through (e) sequentially to said rearward end of said semi-trailer toproduce a filled semi-trailer with stacks of two automobiles each. 2.The method of claim 1 further comprising the additional steps of:(a)transporting one or more of said filled semi-trailers from a point oforigin to a railcar loading facility; (b) loading one or more of saidsemi-trailers onto railroad flatcars in piggyback fashion; (c)transporting said railroad flatcar to a first point of destination; (d)unloading said filled semi-trailers at said first point of destination;(e) transporting said filled semi-trailers to a second point ofdestination; (f) unloading said automobiles from said semi-trailers byreversing steps (a)-(e) of claim 1 sequentially until said semi-traileris emptied of said automobiles and said lifts; (g) accumulating saidlifts at said second point of destination; and (h) shipping said liftsat periodic intervals to said point of origin.